The price of a chip falls by approximately 67% every year : GMAT Problem Solving (PS)
Check GMAT Club Decision Tracker for the Latest School Decision Releases http://gmatclub.com/AppTrack

 It is currently 22 Jan 2017, 00:59

GMAT Club Daily Prep

Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

The price of a chip falls by approximately 67% every year

Author Message
TAGS:

Hide Tags

Intern
Joined: 09 Mar 2013
Posts: 10
Location: India
Followers: 0

Kudos [?]: 12 [1] , given: 8

The price of a chip falls by approximately 67% every year [#permalink]

Show Tags

16 May 2013, 23:23
1
KUDOS
1
This post was
BOOKMARKED
00:00

Difficulty:

(N/A)

Question Stats:

100% (01:59) correct 0% (00:00) wrong based on 16 sessions

HideShow timer Statistics

The price of a chip falls by approximately 67% every year. In approximately how many years will the price of an $81 chip become$1?

I got his question in a document and it doesnt contain any options. Can you help me to resolve this.
Math Expert
Joined: 02 Sep 2009
Posts: 36590
Followers: 7092

Kudos [?]: 93390 [3] , given: 10557

Re: The price of a chip falls by approximately 67% every year [#permalink]

Show Tags

16 May 2013, 23:33
3
KUDOS
Expert's post
rohanchowdhary wrote:
The price of a chip falls by approximately 67% every year. In approximately how many years will the price of an $81 chip become$1?

I got his question in a document and it doesnt contain any options. Can you help me to resolve this.

67%=~2/3, which means that the price of a chip becomes 1/3 of the price in a year.

In 1 year the price will be 81*1/3=$27; In 2 year the price will be 27*1/3=$9;
In 3 year the price will be 9*1/3=$3; In 4 year the price will be 3*1/3=$1.

Hope it helps.
_________________
Intern
Joined: 09 Mar 2013
Posts: 10
Location: India
Followers: 0

Kudos [?]: 12 [0], given: 8

Re: The price of a chip falls by approximately 67% every year [#permalink]

Show Tags

16 May 2013, 23:52
+1 Kudos Brunel.

I never though in this way, this si a new way i can drive on to my result.
Intern
Joined: 04 May 2013
Posts: 19
Location: Azerbaijan
Concentration: Finance, General Management
GMAT 1: 710 Q49 V38
Followers: 0

Kudos [?]: 11 [2] , given: 39

Re: The price of a chip falls by approximately 67% every year [#permalink]

Show Tags

22 May 2013, 06:55
2
KUDOS
P0 = 81 (price of the chip at 0 moment)
P1 = 1/3 * P0 (67% price decrease means new price = 1/3 of the old price)
P(k+1) = P0 * (1/3)^k
81 * (1/3) ^ k = 1 leads to (1/3)^k = 1/81 = (1/3)^4 so k = 4
GMAT Club Legend
Joined: 09 Sep 2013
Posts: 13494
Followers: 576

Kudos [?]: 163 [0], given: 0

Re: The price of a chip falls by approximately 67% every year [#permalink]

Show Tags

22 Oct 2015, 07:18
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________
Director
Joined: 11 Sep 2015
Posts: 902
Followers: 106

Kudos [?]: 867 [1] , given: 108

Re: The price of a chip falls by approximately 67% every year [#permalink]

Show Tags

22 Oct 2015, 10:45
1
KUDOS
Bunuel is using something I call a Growth Table approach. So, rather than trying to formulate the correct answer at once, we can just take the time to list successive values until we get to where we need to be.

For more on this, check out our free video - http://www.gmatprepnow.com/module/gmat- ... /video/929
Afterwards, you can practice with this question - http://www.gmatprepnow.com/module/gmat- ... /video/930

Cheers,
Brent
_________________

Brent Hanneson – Founder of gmatprepnow.com

Brent also tutors students for the GMAT

Director
Joined: 23 Jan 2013
Posts: 579
Schools: Cambridge'16
Followers: 1

Kudos [?]: 42 [0], given: 40

Re: The price of a chip falls by approximately 67% every year [#permalink]

Show Tags

27 Oct 2015, 22:13
we need to find membership in Geometric progression

1 - searched number
81 - first term
1/3 - r (common ratio)

1=81*1/3^(n-1)
1/3^(n-1)=1/81

n-1=4 meaning that 1 will come after 4th year
Re: The price of a chip falls by approximately 67% every year   [#permalink] 27 Oct 2015, 22:13
Similar topics Replies Last post
Similar
Topics:
2 Approximately what percent of the employees with 5 or more years... 2 15 Dec 2015, 13:08
4 The population in a certain town doubles every 5 years. Approximately 6 11 Feb 2015, 05:46
4 One out of every 1000 computer chips is defective. If 2 out of every 3 5 07 Jan 2015, 06:32
The population of a bacteria culture doubles every 2 minutes. Approxim 1 17 Feb 2011, 03:26
10 The price of a microchip declines by 67 percent every 6 months. At thi 12 09 Jul 2007, 17:57
Display posts from previous: Sort by